Ecological Revitalization
and Attractive Nuisance Issues
Fact Sheets on Ecological Revitalization
This fact sheet is the third in a series of fact
sheets related to ecological revitalization.
The first two fact sheets on "Frequently Asked
Questions About Ecological Revitalization
of Superfund Sites", EPA 542-F-06-002,
and "Revegetation of Landfills and Waste
Containment Areas", EPA 542-F-06-001,
can be found at http://www.cluin.org/
ecorevitalization.
Introduction
The U.S. Environmental Protection Agency (EPA)
encourages the beneficial reuse of Superfund,
Brownfields, and other contaminated sites while
protecting human health and the environment.
Superfund sites are being cleaned up and restored
while integrating natural features such as wetlands,
meadows, streams, and ponds to provide habitat for
terrestrial and aquatic plants and animals, and for low-
impact or passive recreation, such as hiking and bird
watching. In addition, many sites redeveloped primarily
for other purposes, such as commercial or recreational
facilities, also contain significant ecological resources
or green space.
The potential exposure of wildlife can be a concern
when waste or contaminants remain on a site following
cleanup (i.e., attractive nuisance), but it need not prevent
the ecological revitalization of that site. At many
successfully redeveloped sites, contaminated material
has been left on the property in containment systems
designed to protect people, wildlife, and the environment
from exposure and prevent contaminant migration. On-
siteor in situ remediation of contamination is used when
it is impractical or unnecessary to completely remove
all the contaminants. To prevent long-term risks to
human health and the environment, including attractive
nuisance issues, redevelopment planners integrate
appropriate exposure reduction strategies, monitoring,
and maintenance into the remedy design.
EPA is sensitive to attractive nuisance issues and has been conducting research and compiling references and case
studies in this area. This fact sheet, the third in a series of fact sheets on ecological revitalization of contaminated
sites developed by EPA Office of Superfund Remediation and Technology Innovation (OSRTI), discusses how to
identify, assess, and manage potential attractive nuisance issues during ecological revitalization of Superfund
sites and presents case studies that illustrate a variety of attractive nuisance issues and how they were managed.
The information is intended for EPA site managers, state agency site managers, consultants, and others interested
in the ecological restoration of contaminated sites.
Various information sources were used to prepare this fact sheet. These and additional information resources
are listed at the end of the fact sheet.
Ecological revitalization of a Superfund site is
the process of returning a site to a functioning and
sustainable use. Ecological revitalization converts a
site closer to a natural state, increasing or improving
habitat for plants and animals by integrating
components that are compatible with the remediation
activities that ensure the protection of human
health and the environment. Although ecological
revitalization can be used to create habitat as a
specific goal, when habitat mitigation is required,
it also can be used to complement or enhance a
traditional cleanup method; as a green remediation
technology to remove or stabilize contaminants; or
reduce erosion while providing valuable wildlife
habitat.
What is an attractive nuisance?
Once the basic physical and biological components of a viable habitat or ecosystem have been established
as part of the ecological revitalization of a site, wildlife use is expected to change with either different or more
diverse wildlife present and/or greater activity. For the purposes of the Superfund Program, an attractive nuisance
1
-------
Selected Benefits of Ecological
Revitalization
Removes stigma associated with prior waste sites
Helps address or remove contamination
Enhances property values
Provides recreational uses for local residents
Improves soil health and supports diverse
vegetation
Creates wildlife habitat
Contributes to a green corridor
Can reduce erosion, sequester carbon, and
control landfill leachate
Protects surface and groundwater from potential
contamination
refers to an area, habitat, or feature that is attractive
to wildlife and has, or has the potential to have, waste
or contaminants left on site that are harmful to plants
or animals after a completed remedial action. For the
purposes of this fact sheet, the definition of attractive
nuisance is strictly wildlife-focused and does not
consider the potential for increased human activity at
a site as an attractive nuisance.
One example is an abandoned mining site that is
barren and void of life. After lime-treated biosolids
were incorporated to complex the metals of concern,
the health of the soil (fertility and general suitability to
support root growth) improved to permit revegetation
with native plants and promote a self-sustaining
ecosystem as habitat for nongame species. Once
the plants were established, animal life became re-
established. Because the metals remained in the
soil, the metals could move through the food chain to
adversely affect animals at the top of the food chain
(e.g., raptors). Thus, because no animals were present
on the site prior to its revitalization, a potential attractive
nuisance was created.
Why are attractive nuisance issues
a concern?
An attractive nuisance can potentially cause harm
to wildlife if (1) an exposure pathway exists from
contaminants left on site that could directly harm wildlife
or could travel up the food chain or (2) wildlife interfere
with the remedy, thereby creating an exposure pathway.
While a remediated site may not create an attractive
nuisance, project managers need to understand the
nature of the contaminants present and the potential
for exposure when developing plans to modify habitat
that may attract wildlife. For example, if more than
one operable unit (OU) is present on a site, animals
attracted to an ecologically revitalized portion of the
site might access adjacent, unremediated OUs or
nearby contaminated areas and become exposed to
contamination.
Site managers and developers may need to address
the potential for contaminant bioaccumulation (i.e., the
retention and buildup of chemicals) in plant and animal
tissues. Bioaccumulation can result in biomagnification,
which is increasing contaminant concentrations in the
tissues of organisms proceeding up in the food chain
to top predators (including humans). These processes
can result in an organism having contaminant
concentrations higher than concentrations in the
surrounding environment or the organism's immediate
food source.
EPA recommends that site managers and developers
consider both exposure pathways and the ways in
which wildlife attracted to the site can affect exposure
pathways by interfering with the remedy, such as a
cap.
Because of the variety of factors that affect wildlife
behavior and ecosystems, it may be difficult to
Ongoing EPA Research
Survival studies and tissue analyses conducted by EPA's Environmental Response Team (ERT) at three former
mining sites (Bunker Hill, Idaho; Leadville, Colorado; and Jasper County, Missouri) show that these sites can
become functional and support healthy wildlife habitat. Each site was originally barren but was treated with soil
amendments. Results from earthworm and small mammal studies have shown that the bioavailability of heavy
metals present on site was dramatically reduced after being treated with soil amendments and that wildlife attracted
to the site are not unacceptably exposed to the site contaminants. For more information, contact Mark Sprenger, EPA
ERT (sprenger.mark@epa.gov or (732) 906-6826).
-------
anticipate all potential consequences of a newly created
or altered ecosystem. However, to the extent possible,
it is recommended that project managers be aware of,
and manage, attractive nuisance issues, and consult
with their Biological Technical Assistance Group (BTAG)
or site biologist for measures to reduce or eliminate
attractive nuisance issues.
How do I assess potential
attractive nuisance issues at my
site?
It is essential to consider potential ecological risk
throughout the Rl process and conduct an ecological
risk assessment thoroughly to avoid potential attractive
nuisance issues. Information on conducting an
ecological risk assessment is included in the Ecological
Risk Assessment Guidance for Superfuna1: Process
for Designing and Conducting Ecological Risk
Assessments - Interim Final (http://www.epa.gov/
oswer/riskassessment/ecorisk/ecorisk.htm). In addition
to addressing human health concerns associated with
the selected end use of the site, an ecological risk
assessment is necessary to determine appropriate
cleanup goals for protecting plants and wildlife. The
ecological risk assessment will evaluate the potential
for adverse ecological effects and bioaccumulation of
contaminants that could occur as a result of exposure
to contaminants left on-site. If ecological concerns are
considered throughout the Rl process, then information
associated with attractive nuisance issues would have
already been collected. For example, information
gathered from an endangered species survey conducted
during Section 7 consultation of the Rl process could
be used during design of the remedy to reduce the
potential for bioaccumulation and exposure of plants
and animals to contaminated material, and to ensure
that the site is not an attractive nuisance, and does not
pose an ecological risk. At the Bunker Hill Superfund
Lake Apopka Attractive Nuisance Issue
When farmland at Lake Apopka, Florida, was
converted to a marsh area designed to enhance
wildlife habitat, an environmental risk assessment
showed that pesticide concentrations might affect
wildlife in the area. Although contaminated areas
were excavated prior to wetland revitalization,
hundreds of migrating birds stopping at the newly
created marsh area died of pesticide poisoning.
The birds, which were attracted by the lake, preyed
on fish in nearby ditches and small pools that
were contaminated with pesticides. This incident
demonstrates the importance of understanding all
potential exposure pathways, including temporary
site conditions created during the construction phase
in addition to final site conditions created by a
remedial action, to ensure that an attractive nuisance
is not created during site revitalization.
site in Idaho, root-zone soil was amended to reduce
or prevent the bioavailability of many heavy metals
to plants (see case study 4 below). The amendments
reduced both accessibility and bioavailability of the
heavy metals and restored ecosystem function. The
site is currently a wetland in a highly visible area and
provides wildlife habitat.
It is recommended that site managers consider the
future use of the site as well as the wildlife that
would be attracted to features present once the
ecological revitalization is complete. If waste is to
be left on site, evaluation of all potential exposure
pathways is necessary to determine whether any
plants will bioaccumulate contaminants or any of the
wildlife attracted to the area could be harmed. The
conceptual site model that was developed as part of
the ecological risk assessment for the site could be
used to identify potential post-remediation exposure
pathways for wildlife. In addition, the site-specific
EPA Initiatives
EPA's Superfund Redevelopment Initiative (SRI) focuses on cleaning up Superfund sites and making them protective
of human health and the environment while considering future use opportunities and integrating appropriate
reuse options into the cleanup process. SRI supports all reuse types, especially ecological revitalization. For more
information on SRI, please visit the following website: http://www.epa.gov/superfund/programs/recycle/index.htm
EPA developed the Return to Use (RTU) Initiative as part of the SRI and is designed to remove barriers to appropriate
reuse once cleanup is completed. For more information on RTU, please visit the following website: http://www.epa.
gov/superfund/programs/recycle/rtu/index.htm
-------
ecc
cological risk-based clean-up goals considered during
the development of clean-up options and coordinated
with stakeholders, such as property owners and the
community, will prevent or minimize the creation of an
attractive nuisance.
When sampling during an Rl, EPA recommends that
data collected from sampling activities provide the
information necessary for the ecological risk assessment
and consideration of potential attractive nuisance
sues. Specifically, the following are recommended:
The sampling plan could include appropriate
multiple media exposure pathway sampling,
such as surface water, sediments, surface and
subsurface soils, and groundwater. Consult your
regional technical expert (for example, BTAG) to
assist in developing your plan.
The sampling locations could be determined to
collect information for both human health and
ecological risk analyses. For example, in addition
to soil sampling for human health, incorporate
ecological aspects as well, such as wetlands or
other sampling into the plan, if applicable.
Analytes could include those that will allow
for an evaluation of both human health and
ecological risk. See Exhibit 1 at the end of
this fact sheet for information about sensitive
receptors and exposure pathways for a variety
of contaminants. In addition to an analysis for
potential contaminants of concern, samples could
be collected and analyzed for parameters such as
total organic carbon to assess the bioavailability
of contaminants.
Consult with the laboratory prior to conducting
sampling activities because some analyses do
not have a low enough reporting limit to assess
ecological risk.
Soil Remediation, Revitalization, and
Reuse: Technical Performance Measures
When remediating and reusing a Superfund,
RCRA, or Brownfields site, there is a hurdle for
all stakeholders, including regulators, to face.
The hurdle is how to determine what technical
performance measures (TPM) or success criteria
should be used to evaluate if the remediation
worked well enough to support the beneficial
reuse of the site. To answer this question, a
web-based tool was developed to provide a
tool which can be used to assist in the selection
of appropriate TPMs for the evaluation of soil
remediation using in-situ remediation techniques,
such as soil amendments. This was completed
by drawing on the collective knowledge and
experience of experts to identify and document
a core set of commercially available, cost
effective, and proven TPMs. This web-based
tool is intended to be used by site project
managers and their technical support team
and can be found at http://www.cluin.org/
ecorevitalization.
Additional information might be needed for consideration
of potential attractive nuisance issues, as shown in the
following examples:
Soil amendments as part of the remedy might have
changed the bioavailability of metals. New data
would be needed to demonstrate the efficacy of
this treatment. See text box above.
A groundwater pump-and-treat system has been
installed to address human health concerns. New
data on a groundwater seep would be needed
prior to creating an emergent wetland habitat.
Additional Assistance
Establishing remediation goals for ecological receptors can be challenging and less prescribed than
establishing goals to protect human health because of: (1) the large variation in the species and
populations of receptors present at sites; (2) the differences in receptor susceptibility to contaminants;
and (3) wide variations in environmental bioavailability of many contaminants in different media. For
these reasons, it is recommended that an ecological risk assessment be conducted with the assistance
of an expert. For assistance in completing an ecological risk assessment, contact the appropriate
risk assessors for your region (in most cases, this is the BTAG) or the ERT (http://www.ert.org/). For
additional information on the role of BTAGs, visit the following website: http://www.epa.gov/oswer/
riskassessment/ecoup/pdf/vl nol .pdf. The regional BTAG web sites, provided at the end of this fact
sheet, provide contact information for BTAG members.
-------
How do I manage attractive
nuisance issues at my site?
The potential for an attractive nuisance exists if waste
or contaminants are left on site, whether contained or
remediated in place. However, exposure pathways or
other attractive nuisance issues can be eliminated or
minimized through careful planning and consideration
throughout the remediation process. The following
activities can be employed to manage a potential
attractive nuisance:
Eliminate the exposure pathway through traditional
or alternative remediation technologies. In addition,
careful selection of habitat goals and plants can
help to ensure that adequate barriers remain intact
between wildlife and residual contamination. If
contaminant uptake by vegetation is a potential
issue and not part of the remedy, supplemental
measures are recommended, including use of
additional cover or soil amendments. Also,
avoid conditions that will attract unwanted plant
or wildlife species to the site. Artificial habitat
can be constructed to maintain elimination of
exposure pathways. Prevent invasive plants from
taking over by selecting native plant species
adapted to site-specific conditions. Plants can
also be incorporated or wildlife introduced to
reduce the attractiveness of the site to wildlife
that could potentially damage the remedy. For
example, at Rocky Mountain Arsenal, Colorado,
one consideration during plant selection was
height at maturity to deter prairie dog invasion
and a biota intrusion layer of crushed concrete
was added to the containment system as a barrier
to badgers and other burrowing animals (for
additional information on exposure pathways,
visit the following website: http://www.epa.gov/
oswer/riskassessment/ecorisk/ecorisk.htm).
Create habitat appropriate for the site to reduce
the attractiveness of a contaminated site to wildlife.
For example, high selenium concentrations in a
wetland area at the Kennecott North and South
Zone site in Salt Lake County, Utah, caused EPA
to recommend covering the wetland and capping
the area (see case study 3 below). Rather than
restoring the wetlands on site and creating an
attractive nuisance (i.e., selenium exposure to
wildlife using the wetland), a more appropriate
upland site was created to avoid attractive
nuisance issues and a wetland mitigation bank
was created in an appropriate location.
Conduct routine maintenance to ensure that
exposure pathways do not become available over
time. These activities would be included in a long-
term operation and maintenance (O&M) plan.
An example of routine maintenance is inspecting
and repairing a containment cap as necessary
to ensure it is kept intact. Visual inspection of
habitat conditions is important to prevent attractive
nuisance issues from developing. Activities such as
removing burrowing or other wildlife species that
could damage the remedy as well as vegetation
that would attract nuisance wildlife, maintaining
the health of the vegetation, and observing wildlife
populations could be included in the O&M plan.
As part of the long-term monitoring plan, confirm
that the site does not become an attractive nuisance
and that contaminants are not accumulating to
levels that would be toxic to wildlife. Monitoring
activities could include sampling of soil,
surface water, vegetation, or animal tissue to
monitor the effectiveness of the remedy and any
bioaccumulation or biomagnification concerns;
conducting wildlife counts to monitor population
health; and monitoring for nuisance plants,
insects, and wildlife (that could harm the remedy)
to evaluate the need for control measures. If
long-term monitoring indicates that an attractive
nuisance develops, modify the long-term O&M
plan as necessary.
Attractive nuisance issues are not
likely to be a problem if:
The site is remediated in a way
that appropriately considers
attractive nuisance issues
Initial studies consider potential
attractive nuisance issues
Sampling and monitoring data
is used to assess potential risk to
wildlife
Any risks are recognized and
eliminated or properly managed
-------
lase Studies
This section includes brief descriptions of several sites that considered attractive nuisance issues during ecological
revitalization of the site.
Case Study 1
Site Information Name: E-Pond Solid Waste Management Unit (SWMU), RCRA Corrective Action, Lima, Ohio
Description: The E-Pond (SWMU 62) is located adjacent to the west bank of the Ottawa River,
outside the operational section of a petroleum refinery. E-Pond consists of two former ponds and one
former landfill that encompass approximately 23 acres. The northern pond was used to dewater, by
evaporation, solid wastes that were obtained from an on-refinery stormwater retention basin. The
southern pond was used to dispose of the solid wastes from the northern pond after the material was
stabilized with soil and fly ash. A landfill area received refinery wastes including sludge, emulsion plant
vacuum filter cake, acid pond sludge, leaded tank bottoms, API separator sludge, and slop oil emulsions.
Site Contact Thomas Matheson, EPA Region 5, Phone: (312) 886-7569, E-mail: matheson.thomas@epa.gov
Site-Specific
Resources
Site Conditions:
Attractive
Nuisance Issues
Site
Revitalization:
Attractive
Nuisance
Management
http://www.epa.gov/epaoswer/hazwaste/ca/curriculum/download/eco-rec.pdf
http://www.epa.gov/epaoswer/hazwaste/ca/curriculum/download/eco-rec.ppt
E-Pond was investigated, and several samples were collected to provide the information necessary
to conduct a risk assessment for both human health and ecological receptors. Based on these risk
assessments, it was determined that the surface soils presented risks to ecological receptors (soil
invertebrates, plants, and wildlife: short-tailed shrew, deer mouse, and American robin) and was on the
high end of the human health risk range due to elevated levels of chromium, antimony, thallium, and PCB
1 248 in the surface soil. Therefore, the risk from surface soils had to be addressed.
A site conceptual plan was developed, taking into consideration the risk levels at the site. The plan calls
for creation of:
Prairie habitat consisting of native grasses and flowers
Native tree and shrub clusters to provide cover for wildlife
A butterfly garden
Interpretive areas and educational opportunities
Artificial nesting structures to be built on the cover settling plates, which will help in locating the
plates
A synthetic root barrier will inhibit the growth of roots into the waste, including the long root systems of
native grasses and flowers, and will deter small mammals from burrowing into the waste. In addition,
the 12-inch protective soil cover will eliminate exposure of soil biota to soil with elevated contaminant
levels, thus reducing risk to acceptable levels. Clean soil will be enhanced with biosolids to augment the
organic content of the clean soil. A berm with trees will be constructed in the northern area of the site
to provide a barrier between E-Pond and a construction debris landfill to the north. The O&M plan will
ensure the long-term integrity of the remedy.
For additional information on land application of biosolids and compost, go to
http://www.epa.gov/own/mtb/biosolids
and http://www.epa.gov/compost
-------
Case Study 2
Site Information Name: Morgantown Ordnance Works Disposal Area, OUT, Monongalia County, West Virginia
Description: The Ordnance Works Disposal Area site consists of a 6-acre disposal area and a
manufacturing plant area, which is over 100 acres. Since 1 941, many private companies have
operated chemical production facilities at this site; operations included ammonia and methanol
production, coke plant operations, and production of various other organic chemicals. Contaminated
materials from the manufacturing processes were disposed of in the disposal area (OU1), which includes
a landfill, former lagoons, and contaminated soils and sediments.
Site Contact Chris Corbett, EPA Region 3, Phone: (215) 814-3220, E-mail: corbett.chris@epa.gov
Site-Specific http://epa.gov/reg3hwmd/npl/WVD000850404.htm
Resources
Site Conditions:
Attractive
Nuisance Issues
Site
Revitalization:
Attractive
Nuisance
Management
At OU1, sediments and soils in and around the landfill and former lagoon area are contaminated
with heavy metals and polycyclic aromatic hydrocarbons (PAH). Initially, the cleanup remedy for OU1
included construction of a cap on the landfill; bioremediation of soils and sediments contaminated with
PAHs; solidification of soils contaminated with heavy metals; and post-remediation monitoring to ensure
the effectiveness of the cleanup action. Treatability studies completed for bioremediation indicated that
bioremediation could not meet cleanup standards within a reasonable time frame and was not cost-
effective.
The revised remedy included construction of a cap, removal of contaminated soil and sediments, and
construction of three consecutive treatment wetlands (Ponds 1, 2, and 3) to treat landfill leachate. The
first pond is primarily a settling basin for heavier particulates. Cattails were established to ensure
aerobic conditions. The second pond is anaerobic to reduce zinc and copper concentrations. The third
or polishing pond removes any remaining metals from the leachate and reduces biochemical oxygen
demand (BOD). This shallow pond was planted with cattails to dissuade wildlife from entering it.
Wildlife needs to be kept away from the ponds to prevent contact with landfill leachate.
In order for the wetlands to operate as intended, vegetation was required to be absent from Pond 2
to maintain anaerobic conditions, but vegetation would need to flourish in Ponds 1 and 3 and remain
dense enough to ensure aerobic conditions and deter wildlife. The treatment wetlands were inspected
every 6 months during the first 2 years of the O&M period, and then inspected annually. Field
observations during the regular inspections included (1) recording wildlife occurrences within the system
habitat and the potential for wildlife exposure to residual leachate, (2) assessing sedimentation and
erosion, and (3) assuring adequate aquatic vegetation in Ponds 1 and 3 and confirming negligible or
nonexistent aquatic vegetation in Pond 2. The effectiveness of the treatment wetlands was also being
monitored quarterly through water quality sampling activities.
To mitigate the use of wetlands for treatment, 1.05 acres of wetlands were constructed along the
Monongahela River.
Information about wetland mitigation requirements may be obtained at
http://www.epa.gov/wetlandsmitigation. Also refer to the "Frequently Asked Questions About
Ecological Revitalization of Superfund Sites'7 fact sheet (EPA 542-F-06-002).
-------
Case Study 3
Site Information Name: Kennecott North and South Zone Sites, Salt Lake County, Utah
Description: Mining in the area began in the 1 860s, with copper being the primary metal produced.
Since around 1900, Kennecott has operated a wide variety of mineral processing and production
facilities on site. Kennecott sent much of the mineral processing waste and copper ore from these
operations north to the Kennecott Site (North Zone). Tailings waste produced in the South Zone was
shipped to the North Zone by slurry and rail.
Site Contact Rebecca Thomas, EPA Region 8, Phone: (303) 312-6552, E-mail: thomas.rebecca@epa.gov
Site-Specific http://oaspub.epa. gov/enviro/cerclis_web.description_report?pgm_sys_id=UTD070926811
Resources http://www.epa.gov/superfund/programs/aml/tech/kennecott.pdf
http://www.epa.gov/superfund/sites/fiveyear/f04-08002.pdf
Site Conditions:
Attractive
Nuisance Issues
The North Zone covers a large area, and sources of contamination include the 5,700-acre tailings pond,
a slag pile, and the refinery evaporation pond. The main contaminants of concern are lead, arsenic,
and selenium. The South Zone includes wastes associated with extracting and concentrating copper ore.
The main sources identified were an open pit, creeks and reservoirs, tailings (including Lark Tailings),
evaporation ponds, dumps, and residential soils. Contaminants found in waste sources at the South
Zone include arsenic, cadmium, chromium, copper, lead, nickel, selenium, silver, and zinc.
Wetlands, springs, creeks, and marshes exist on site and have been used for a variety of purposes over
the years, including storage areas for process water and dumping grounds for smelter and refinery
wastes. There is concern that maintaining some of the wetlands would create an attractive nuisance
because of high selenium concentrations in the water.
Site
Revitalization:
Attractive
Nuisance
Management
Wetlands with substantial amounts of selenium are not recommended for continued use as wetlands
because of the threat to wildlife that would be attracted to the wetland areas. EPA recommended that the
wetland habitat be removed by covering the wetlands and zoning the capped areas for light industrial
activity. Other wetland areas on site were revitalized without creating attractive nuisance issues and are
recommended for future use as wildlife habitat and potential passive recreational. In fact, over 1,000
acres of new wildlife habitat or open space was created, including a wetlands mitigation bank.
More information on the revitalization and reuse of abandoned mine lands (AMI) can be
found at http://www.epa.gov/superfund/programs/aml/revital/index.htm
8
-------
West Page Swamp, Idaho -
Before Ecological Revitalization.
Source: Dr. Sally Brown, University of Washington
West Page Swamp, Idaho -
After Ecological Revitalization.
Source: Dr. Sally Brown, University of Washington
Case Study 4
Site Information Name: West Page Swamp (Bunker Hill NPL Site), Shoshone County, Idaho
Description: West Page Swamp is a naturally occurring 15-acre wetland that is part of the Coeur
d'Alene River system in Northern Idaho. It was used as a tailings repository in the 1 920s for a mill that
processed zinc and lead ore.
Site Contact Harry Compton, EPA ERT, Phone: (732) 321-6751, E-mail: compton.harry@epa.gov
Site-Specific Interstate Technology and Regulatory Council (ITRC). 2004. Making the Case for Ecological
Resources Enhancement ECO-1. Washington D.C.: ITRC and Wildlife Habitat Council (WHC).
On-Line Address: http://www.itrcweb.org
Site Conditions: The soil material in the swamp consists of highly contaminated (up to 3 percent lead and 1.5 percent
Attractive z'nc) tailings. These materials were sufficiently toxic that the swamp showed no evidence of ecosystem
Nuisance Issues functi°n- Waterfowl feeding and nesting in these areas have routinely developed acute lead toxicity from
ingesting the contaminated sediment.
To restore wetland function to the site, a cap consisting of biosolids compost and wood ash was spread
over the surface of the tailings. Stakeholder concerns were primarily related to the ability of the surface
amendment to reduce the bioavailability of the underlying metals at the site. There was concern that the
site would become an attractive nuisance for wildlife.
Site
Revitalization:
Attractive
Nuisance
Management
The cap was sufficient to reduce both accessibility and bioavailability of the underlying tailings and
restore ecosystem function characteristic of a naturally occurring wetland. The site is currently a
wetland in a highly visible area. It provides wildlife habitat and helps a community that was known for
undisturbed natural beauty recapture that image after mining and smelting operations ceased.
Stakeholders remain concerned that with leaving a contaminant in place, the remedy will only be
temporary. An important component of the remedial plan includes monitoring, especially because the
remedy does not completely remove contaminants from the site. Groundwater and surface water wells
were installed throughout the site and are monitored quarterly or annually as part of the long-term O&M
plan.
-------
Case Study 5
Site
Information
Site Contact
Site-Specific
Resources
Site
Conditions:
Attractive
Nuisance
Issues
Site
Revitalization:
Attractive
Nuisance
Management
Name: Tailings Associated with the California Gulch Superfund Site, Leadville, Colorado
Description: The California Gulch Superfund Site in Lake County, Colorado, encompasses more than
1 8 square miles in the Rocky Mountains, about 1 20 miles west of Denver. Mining, mineral processing,
and smelting activities there produced gold, silver, lead, copper, manganese, and zinc for more than 1 30
continuous years. The site was listed on the National Priorities List in 1 983, and included deposition of mine
tailings along the Upper Arkansas River.
For over 100 years, these high-pyrite mine tailings have been eroded and re-deposited along the Upper
Arkansas River and have created a 10-mile stretch of barren mine deposits. In addition, high metal
concentrations in irrigated pastures had contributed to elevated rates of plant toxicity and high mortality in
grazing livestock.
Rebecca Thomas, EPA Region 8, Phone: (303) 312-6652, E-mail: thomas.rebecca@epa.gov
Michael Holmes, EPA Region 8, Phone: (303) 312-6607, E-mail: holmes.michael@epa.gov
Michael Zimmerman, EPA Region 8, Phone: (303) 312-6828, E-mail: zimmerman.mike@epa.gov
http://clu-in.org/products/newsltrs/tnandt/view.cfm?issue=0705.cfm
http://jeq.scijournals.org/cgi/reprint/34/1 /1 39.pdf
http://faculty.washington.edu/clh/leadville.html
http://www.epa.gov/superfund/programs/recycle/success/casestud/caLgulch.pdf
The tailings along the Upper Arkansas River have low soil pH; have elevated concentrations of lead,
cadmium, and zinc; and are phytotoxic. Without stabilizing vegetation, erosion would release the tailings
into the river during high water events.
Removal of the tailings was not feasible due to (1) the potential for tailings to enter the river during field
activities, (2) the high cost of replacement topsail, and (3) the difficulty of locating an acceptable repository
for contaminated soil.
High rates of lime amendment were used to neutralize the acidity of the tailings, and municipal biosolids
were applied directly into the tailings. A majority of the 10-mile stretch along the Upper Arkansas River
has been restored and now supports dense vegetation. Analytical sampling conducted by EPA and USDA
indicates that although total soil concentrations of metals of concern have not changed, extractable and
available lead, cadmium, and zinc are now below regulatory standards.
A wide range of earthworm, fish, and small mammal testing was conducted to determine whether the
revitalized habitat was creating an attractive nuisance to the wildlife attracted there. Results showed that
the bioavailability of heavy metals present on site was dramatically reduced after being treated with soil
amendments and that wildlife exposure to metals is within acceptable limits. In addition, cattle grazing
has resumed on land that was barren for more than 80 years, and a public park with a fishing area now
operates on one of the former tailings deposits.
California Gulch Superfund Site, Colorado -
Before Ecological Revitalization.
Source: Michael Holmes, EPA
California Gulch Superfund Site, Colorado
After Ecological Revitalization.
Source: Michael Holmes, EPA
10
-------
Exhibit 1: Sensitive Receptors and Exposure Pathways for Metals and
Organic Contaminants
Contaminant
Sensitive Rece
.2
1
8
|
CO
| Groundwater
_y
"o
1
c
O
Q_
1
ptor
>
^
(U
E
1
t/5
Pathway
1
_c
_ii
S E
* -2
I*
Movement to
groundwater
Movement to
surface water
_c
ju a>
o '
X c
-£ °
11
c a
o F
U «
0
£L
S
3
£
-2 5
= £
_g a>
a. _c
Direct ingestion
of soil, carnivore
Metals
Zinc
Cadmium
Lead
Arsenic
Chromium
Selenium
Mercury
Copper
Aluminum
Manganese
^
^
^
S
-------
References and Additional Information
Interdisciplinary Training for Ecosystem Restoration. On-
line Address: http://www.epa.gov/owow/watershed/
wacademy/training/bkley6.html
Internet Seminars on Ecological Restoration. On-Line Address:
http://www.clu-in.org/studio/seminar.cfm
Interstate Technology and Regulatory Council (ITRC). 2004.
Making the Case for Ecological Enhancement ECO-1 .
Washington D.C.: ITRC and Wildlife Habitat Council (WHC).
On-Line Address: http://www.itrcweb.org
ITRC. 2006. Planning and Promoting Ecological Land Reuse
at Remediated Sites ECO-2. Washington D.C.: Ecological
Land Reuse Team. On-Line Address: http://www.itrcweb.
org
Oak Ridge National Laboratory (ORNL). 2006. Ecological
Risk Analysis: Guidance, Tools, and Applications for
Contaminated Sites. On-Line Address: http://www.esd.ornl.
gov/programs/ecorisk/contam inated_sites.htm I
Opresko, D.M., Sample, B.E., and G.W. Suter. 1993.
"Toxicological Benchmarks for Wildlife." Oak Ridge National
Laboratory, Environmental Restoration Division, Oak Ridge,
Tennessee. Technical Memorandum ES/ER/TM-86.
Sample, B.E., and C.A. Arenal. 1999. "Allometric Models
for Interspecies Extrapolation of Wildlife Toxicity Data." Oak
Ridge National Laboratory, Environmental Sciences Division.
Oak Ridge, Tennessee. April 21.
Sample, B.E., G.W. Suter II, R.A. Efroymson, and D.S. Jones.
1998. "A Guide to the ORNL Ecotoxicological Screening
Benchmarks: Background, Development, and Application."
Environmental Sciences Division Publication No. 4783. Oak
Ridge National Laboratory. Oak Ridge, Tennessee.
Sample, B.E., D.M. Opresko, and G.W. Suter, II. 1996.
"Toxicological Benchmarks for Wildlife: 1996 Revision."
ES/ER/TM-86/R3. Oak Ridge National Laboratory. Oak
Ridge, Tennessee.
Society for Ecological Restoration (SER) International.
2005. Guidelines for Developing and Managing Ecological
Restoration Projects, 2nd Edition. Andre Clewell, John Rieger,
and John Munro. December. On-Line Address: http://www.
ser.org
Sprenger, M.D., Badner, J.R., and Hinzman, R. 2003.
Contaminant Bioavailability Alteration Resulting from Biosolids
Soil Amendment: Pilot Study Results for the Jasper County Site,
Joplin, MO. September.
U.S. Department of the Navy (Navy). 1999. "Navy Policy
for Conducting Ecological Risk Assessment." April 5.
U.S. Environmental Protection Agency (EPA). 1986.
"Recommended Guidelines for Measuring Selected
Environmental Variables in Puget Sound." March.
EPA. 2003. Region 5 RCRA Corrective Action Ecological
Screening Levels. August 22.
EPA. 2005. Interim Ecological Soil Screening Levels. March.
On-Line Address: http://www.epa.gov/ecotox/ecossl/
EPA. GreenScape Program. On-Line Address: www.epa.
gov/greenscapes/
EPA. Superfund Redevelopment Initiative and Return-to-Use
Initiative. On-Line Address: http://www.epa.gov/superfund/
programs/recycle/index.htm
Reference for Exhibit 1: Dr. Sally Brown, University of
Washington
EPA Regional BTAG Web Sites
EPA Region 2: http://www.epa.gov/region02/org/desa_
hsw.htm
EPA Region 3: http://www.epa.gov/reg3hwmd/risk/eco/
index.htm
EPA Region 4: http://www.epa.gov/region4/waste/ots/
index.htm
EPA Region 5: http://www.epa.gov/region5superfund/
ecology/index, htm I
EPA Region 8: http://www.epa.gov/region8/r8risk/
eco.html
Contact Us
If you have any questions or comments on this fact sheet,
or suggestions for future fact sheets, please contact:
Ellen Rubin
(703) 603-0141
rubin.ellen@epa.gov
Scott Fredricks
(703) 603-8771
fredricks.scott@epa.gov
Office of Superfund Remediation
and Technology Innovation
(5203P)
EPA 542-F-06-003
June 2007
www.epa.gov
12
------- |